Elastomeric emitter and methods relating to same

ABSTRACT

An irrigation drip emitter, and methods relating to same, are provided for delivering irrigation water from a supply tube to an emitter outlet at a reduced and relatively constant flow rate. The emitter having at least one movable member for compensating for fluctuations in supply line fluid pressure. In one form the movable member includes a tapered baffle section movable between a first position wherein fluid is allowed to flow over the tapered baffle section and a second position wherein fluid is prevented from flowing over at least a portion of the tapered baffle section and the tapered baffle section effectively lengthening the extent of a pressure reduction passage. In another form, first and second movable members are provided for compensating for such pressure fluctuations. In another form, a plurality of inputs are provided which are movable between first and second positions to compensate for such pressure fluctuations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of prior application Ser. No.13/430,249, filed Mar. 26, 2012, which is hereby incorporated herein byreference in its entirety.

FIELD

The present invention relates to irrigation drip emitters, and moreparticularly, to multiple irrigation drip emitters mounted to a supplytube to form an irrigation assembly or system.

BACKGROUND

Drip emitters are commonly used in irrigation systems to convert waterflowing through a supply tube at a relatively high flow rate to arelatively low flow rate at the outlet of each emitter. Each dripemitter generally includes a housing defining a flow path that reduceshigh pressure water entering the drip emitter into relatively lowpressure water exiting the drip emitter. Multiple drip emitters arecommonly mounted on the inside or outside of a water supply tube. In onetype of system, a large number of drip emitters are mounted at regularand predetermined intervals along the length of the supply tube todistribute water at precise points to surrounding land and vegetation.These emitters may either be mounted internally (i.e., in-line emitters)or externally (i.e., on-line or branch emitters). Some advantages toin-line emitters are that the emitter units are less susceptible tobeing knocked loose from the fluid carrying conduit and the conduit canbe buried underground if desired (i.e., subsurface emitters) whichfurther makes it difficult for the emitter to be inadvertently damaged(e.g., by way of being hit or kicked by a person, hit by a lawnmower ortrimmer, etc.).

In addition to the advantages of in-line emitters, subsurface dripemitters provide numerous advantages over drip emitters located andinstalled above ground. First, they limit water loss due to runoff andevaporation and thereby provide significant savings in waterconsumption. Water may also be used more economically by directing it atprecise locations of the root systems of plants or other desiredsubsurface locations.

Second, subsurface drip emitters provide convenience. They allow theuser to irrigate the surrounding terrain at any time of day or nightwithout restriction. For example, such emitters may be used to waterpark or school grounds at any desired time. Drip emitters located aboveground, on the other hand, may be undesirable at parks and schoolgrounds during daytime hours when children or other individuals arepresent.

Third, subsurface emitters are not easily vandalized, given theirinstallation in a relatively inaccessible location, i.e., underground.Thus, use of such subsurface emitters results in reduced costsassociated with replacing vandalized equipment and with monitoring forthe occurrence of such vandalism. For instance, use of subsurfaceemitters may lessen the costs associated with maintenance of publiclyaccessible areas, such as parks, school grounds, and landscaping aroundcommercial buildings and parking lots.

Fourth, the use of subsurface drip emitters can prevent the distributionof water to undesired terrain, such as roadways and walkways. Morespecifically, the use of subsurface drip emitters prevents undesirable“overspray.” In contrast, above-ground emitters often generate overspraythat disturbs vehicles and/or pedestrians. The above-identifiedadvantages are only illustrative; other advantages exist in connectionwith the use of subsurface drip emitters.

Although some advantages of subsurface emitters are described above, itwould be desirable to provide an improved in-line drip emitter designthat can be used in both subsurface and above ground applications. Forboth applications, there is a need to provide for a relatively constantwater output from each of the emitters in the irrigation system. Morespecifically, it is desirable to provide pressure compensation so as toensure that the flow rate of the first emitter in the system issubstantially the same as the last emitter in the system. Without suchflow rate compensation, the last emitter in a series of emitters willexperience a greater pressure loss than the first. Such pressure lossresults in the inefficient and wasteful use of water.

There is also a need in the irrigation industry to keep drip emittersfor both subsurface and above ground applications from becomingobstructed, which results in insufficient water distribution andpotential plant death. Obstruction of an emitter may result from theintroduction of grit, debris, or other particulate matter from debrisentering the emitter through the supply tube. It is therefore desirableto have an inlet and/or other structures that are of a design to deflectparticles that might otherwise clog flow passages in the body of theemitter. The flow through area of the inlet, however, must also be largeenough to allow proper functioning of the drip emitter.

It is also desirable to provide a drip emitter that minimizes parts andassembly as this will not only make the component less complicated toconstruct and likely save on material costs, but will also reduce thenumber of emitters that do not perform as desired due to misalignedparts, etc. Drip emitters are commonly formed of multi-piece components(e.g., two or more-piece housing structures with separate flexiblediaphragms, etc.) that require individual manufacture of the variousparts of the emitter and then assembly of the parts prior to mounting tothe supply tube. Even slight misalignment of these components duringassembly may result in a malfunctioning drip emitter. Thus, in additionto the above needs, it would be desirable to reduce the number ofcomponents required to make the emitter and the manufacturing steps andtime it takes to create a finished product.

Lastly, it is also desirable to provide a drip emitter that minimizesthe amount of disturbance the emitter causes to the fluid flowingthrough the drip line or conduit to which the emitter is connected.Larger cylindrical emitters are available in the marketplace for in-lineemitter applications, however, these emitters interfere with the flow ofthe fluid traveling through the drip line or tube and introduce moreturbulence to the fluid or system due to the fact they cover and extendinward from the entire inner surface of the drip line or tube. Theincreased mass of the cylindrical unit and the fact it extends about theentire inner surface of the drip line or tube also increases thelikelihood that the emitter will get clogged with grit or otherparticulates (which are more typically present at the wall portion ofthe tube than in the middle of the tube) and/or that the emitter itselfwill form a surface upon which grit or particulates will build-up oninside the drip line and slow the flow of fluid through the drip line orreduce the efficiency of this fluid flow. Thus, there is also a need toreduce the size of in-line emitters and improve the efficiency of thesystems within which these items are mounted.

Accordingly, it has been determined that the need exists for an improvedin-line emitter and methods relating to same which overcomes theaforementioned limitations and which further provides capabilities,features and functions, not available in current bases and methods, andfor an improved method for doing the same.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of severalembodiments of the present invention will be more apparent from thefollowing more particular description thereof, presented in conjunctionwith the following drawings.

FIGS. 1A-F are perspective, top, front, rear, bottom and right endviews, respectively, of a drip emitter embodying features of the presentinvention, with the perspective and right end views illustrating theemitter bonded to the inner side of a drip line or tube (shown in brokenline), the opposite end view (i.e., left end view) being a mirror imageof the end view illustrated;

FIGS. 1G-H are cross-sectional views of the emitter of FIGS. 1A-F takenalong line i-i illustrated in FIG. 1B, with FIG. 1G illustrating thetapered portion of the inner baffle wall at its low pressure position toshow how fluid can flow over the top thereof, and FIG. 1H illustratingthe tapered portion of the inner baffle wall at its high pressureposition to show how fluid is prevented from flowing over the topthereof;

FIGS. 1I-J are charts illustrating the amount of deflection of thetapered portion of the inner baffle wall per increase in pressure atpoints 1 and 2 along the tapered portion as illustrated in FIG. 1B, withFIG. 1I illustrating deflection vs. pressure for an elastomeric emitterbody material having a Durometer value of 50 and FIG. 1J illustratingdeflection vs. pressure for an elastomeric emitter body material havinga Durometer value of 75.

FIGS. 2A-D are perspective, top, rear and front views, respectively, ofan alternate drip emitter embodying features of the present inventionwherein a tongue and fork type arrangement is used instead of a singletapered portion to compensate for pressure fluctuations that the emitteris exposed to when inserted in a supply line, the end and bottom viewsof this embodiment looking similar to those of the embodiment of FIGS.1A-F;

FIGS. 2E-F are cross-sectional views of the emitter of FIGS. 2A-D takenalong line i-i illustrated in FIG. 2B;

FIGS. 3A-D and F are perspective, top, front, rear, and bottom views,respectively, of an alternate drip emitter embodying features of thepresent invention wherein inlet openings of varying heights are used tocompensate for pressure fluctuations that the emitter is exposed to wheninserted in a supply line;

FIGS. 3E and G are additional rear and perspective views, respectively,of the embodiment of FIGS. 3A-D wherein FIG. 3E illustrates the inletopening sleeves at a higher pressure position showing at least some ofthe inlet openings being closed to compensate for an increase inpressure and FIG. 3G illustrates the embodiment of FIGS. 3A-D from anrear right perspective instead of the front right perspectiveillustrated in FIG. 3A;

FIG. 4 is a perspective view of an alternate drip emitter and drip lineembodying features of the present invention and illustrating an emitterwith a baffle design which opens and closes in a non-sequential manner;

FIGS. 5A-B are perspective views of an alternate drip emitter and dripline embodying features of the present invention wherein thepressure-reducing flow channel is made-up of baffles with flexible teeththat move in response to fluid flow through the emitter body;

FIG. 6A is a perspective view of an alternate drip emitter and drip lineembodying features of the present invention wherein thepressure-reducing flow channel is made-up of baffles with hollow teethor teeth that enlarge as fluid pressure increases within the supply lineso that the pressure-reducing flow channel has a first cross-section atlower fluid pressures and a second cross-section, smaller than thefirst, at higher fluid pressures to compensate for the increase in fluidpressure so that the emitter and drip line trickle fluid at a generallyconstant or desired rate;

FIGS. 6B-C are perspective views of a portion of the flow channel ofFIG. 6A illustrating the hollow teeth of the baffle partially enlargedand fully enlarged, respectively, in response to increasing fluidpressure showing how the cross-section of the pressure-reducing flowchannel in FIG. 6B has a smaller cross-section than that illustrated inFIG. 6A due to an increase in fluid pressure and showing how thecross-section of the pressure-reducing flow channel of FIG. 6C is evensmaller yet than that illustrated in FIG. 6B due to a further increasein fluid pressure; and

FIG. 6D is a perspective view of a portion of the bottom of the emitterillustrated in FIG. 6A showing the underside of the hollow teeth membersof the baffle and how such surfaces are exposed to the fluid and areaffected by an increase in fluid pressure.

Corresponding reference characters indicate corresponding componentsthroughout the several views of the drawings. Skilled artisans willappreciate that elements in the figures are illustrated for simplicityand clarity and have not necessarily been drawn to scale. For example,the dimensions of some of the elements in the figures may be exaggeratedrelative to other elements to help to improve understanding of variousembodiments of the present invention. Also, common but well-understoodelements that are useful or necessary in a commercially feasibleembodiment are often not depicted in order to facilitate a lessobstructed view of these various embodiments of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIGS. 1A-F, a drip irrigation emitter 10 is provided fordistributing water from a fluid supply source or conduit, such as dripline or tube 70, at a low flow rate. The drip line 70 carriespressurized fluid throughout an irrigation system and preferablyincludes numerous emitters 10 spaced apart at predetermined intervals inthe dip line 70 in order to allow the drip line 70 to be placed above orbelow ground to water and/or treat grass, plants, shrubs, trees or otherlandscaping, or to water agricultural crops of various kinds. In theform illustrated, the emitter 10 includes an integral body 20 whichdefines an inlet 30 connectible to a source of pressurized fluid, anoutlet 40 for discharging the fluid from the emitter body 20, and apressure reducing flow channel or passage 50 between the inlet 30 andoutlet area 40 for reducing the flow of fluid discharged through theoutlet 16. In addition, the emitter body 20 defines a pressurecompensating member 60 for reducing a cross-section of the flow channelin response to an increase in pressure of the pressurized supply linefluid.

In the form illustrated, the emitter body 20 is made of an elastomericmaterial, such as a thermoplastic or thermosetting elastomeric materiallike materials that use ethylene, propylene, styrene, PVC, nitrile,natural rubber, silicone, etc., to form a polymer or copolymer. In apreferred form, the elastomeric material is made of thermoplasticpolyolefin (TPO) and silicone rubber. This combination helps create anemitter and drip line that is capable of withstanding the hightemperatures and harsh chemicals the emitter may be subjected to whilein use. In addition, the emitter is made of a singular or unitaryconstruction rather than having a multi-part construction and/orrequiring the assembly of housing parts, diaphragms, etc. This simpleconstruction makes it easier to manufacture the emitter and makes theemitter more grit-tolerant. More particularly, the simple and flexibleconstruction of the emitter can easily process grit or otherparticulates by expanding to process the grit (aka burping) due to thefact there are no additional housing portions to prevent such expansion.This simple construction also allows the emitter to be flushed moreeasily by allowing line pressure to be increased to process grit out ofthe emitter without concern for damaging the emitter because there areno additional pieces, such as multi-part housings, that limit the amountof movement the emitter can make before breaking or coming apart.

Whereas in conventional emitters, even those having two-piece housings,diaphragms and metering grooves to assist in the flushing of grit, theemitter typically reaches a state where further increases is pressurewill not increase processing of grit. For example, in conventionalemitters, at a certain point of fluid pressure, the pressure on bothsides of the diaphragm will eventually become equal and the emitter willcease processing or burping the grit. In the form illustrated, however,the disclosed emitter will continue to process grit with increases inpressure well beyond when conventional emitters stop processing grit(e.g., when this state of equal pressures on opposite sides of thediaphragm are reached). Thus, line pressure can simply continue to beincreased in order to drive grit through the emitter body. Theelastomeric nature of the emitter body 20 further helps flushing orburping particulates or grit even when simply turning on and off thesupply line.

As best illustrated in FIGS. 1E-F, the body 20 defines a plurality ofslots 21, 22, 23 and 24, extending longitudinally along the bottomsurface of the emitter body 20 which are separated by protrusions, suchas guide ribs 25, 26, 27, 28 and 29. The outer most guide ribs 25 and 29are positioned on the periphery of the bottom surface of emitter body 20while the inner most ribs 26-28 are positioned on an interior portionseparated from the periphery by inlet channel 31. In a preferred form,the inlet channel 31 is sized to deflect foreign materials fromobstructing the inlet 30 or entering the emitter body 20 and guide ribs25-29 have at least one tapered end and run parallel to the longitudinalaxis of the emitter body 20 to further help deflect foreign materialsfrom obstructing the inlet channel 31 or entering the emitter body 20.In the form illustrated, the inlet channel 31 extends continuouslyaround or at a perimeter region of the emitter body 20 and empties intothe inlet 30. More particularly, in the form illustrated, the inletchannel 31 is a generally oval shaped raceway recessed in the bottomsurface of the emitter body 20 having curved ends 31 a, 31 b and longerstraight-aways 31 c, 31 d that run longitudinally along the bottom ofbody 20. The inlet channel has a generally rectangular cross-section andopens into the inlet 30 via a rectangular shaped opening.

The recessed nature and length of inlet channel 31 helps prevent grit orother particulates from entering into the inlet 30 that could clog theemitter 10 or form obstructions preventing the emitter 10 from operatingin the desired manner. More particularly, once installed in the dripline 70, pressurized fluid flows along the bottom side of the emitterbody 20 with some fluid entering into the raceway of inlet channel 31and traveling about the periphery of the emitter body 20 and then,ultimately, into the inlet opening 30. In this manner, the side walls ofchannel 31 serve to deflect grit and other particulates in the fluidfrom entering into the inlet channel 31 and into the inlet opening 30.This prevents the emitter 10 from getting clogged and/or havingobstructions enter the emitter 10 that might otherwise negatively affector compromise the desired operation of the emitter. The circular flowthat is created by the inlet channel 31 further helps ensure that largerparticulates that might fit within the inlet channel 31 will fall out ofor be flushed from the channel 31 as the fluid races about the racewaybefore the fluid enters into the inlet opening 30.

The guide ribs 25-29 serve the dual function of assisting with themounting of the emitter body 20 into the irrigation drip line andfurther help deflect grit or particulates in the pressurized fluid awayfrom the inlet channel 31 and inlet opening 30. More particularly, oneor more of the guide ribs 25-29 may be used by an insertion tool toalign and insert the emitter body 20 into the drip line 70 as the dripline is being extruded. In a preferred form, this is done as the dripline 70 is being extruded so that the upper surfaces of the emitter body20 are bonded or welded to the drip line 70 while the drip line is hotand before it begins to cool. The guide ribs 25-29 may also be taperedor pointed to assist in the initial loading of the emitter body 20 froma bowl sorter and into the inserter or loader used to insert the emitterbody 20 into the freshly extruded drip line 70. Such tapering furtherassists with getting fluid in the supply line to flow between the narrowpassages defined by the ribs 25-29 without causing too much disturbanceor adding too much turbulence to the fluid flowing through the supplyline 70.

In the form illustrated, the guide ribs 25-29 also help prevent grit orother particulates in the pressurized fluid from entering into the inletchannel 31 and inlet opening 30. More particularly, like the sidewallsof inlet channel 31, the ribs 25-29 create narrowed passageways whichhelp deflect larger particulates away from the inlet channel 31 andinlet opening 30. Thus, the ribs 25-29 deflect away larger particulatesfrom the inlet channel 31 and inlet opening 30 and the sidewalls ofinlet channel 31 deflect away smaller particulates that are capable offitting into the narrowed passageways defined by the ribs 25-29. Thisprevents the emitter 10 from getting clogged and/or having obstructionsenter the emitter 10 that might otherwise negatively affect orcompromise the desired operation of the emitter 10.

In the form illustrated, the inlet opening 30 is generally rectangularin shape and of a desired size to ensure that the emitter 10 receives adesired amount of fluid at a desired fluid flow rate in order to operateas desired. In alternate forms, however, the inlet opening 30 may bedesigned in a variety of different shapes and sizes to accommodatespecific desires or applications. For example, in alternate forms, theinlet opening may be designed as more of an elongated slot or slit, orplurality of slot-like openings as illustrated in FIG. 4 (which will bediscussed further below), for receiving fluid but further deflectinggrit or particulates that are small enough to pass through the walls ofinlet channel 31 or it may be designed to cooperate with thepressure-reduction flow channel 50 to start reducing the flow andpressure of the fluid as it enters the emitter body 20 (e.g., the inletmay form a tortuous passage that leads to the pressure-reduction channel50). Similarly, the inlet channel 31 may be designed in a variety ofdifferent shapes and sizes. For example, instead of a generally ovalshape, the inlet channel 31 may be designed to be a smaller slot thatextends over a small portion of emitter body 20 instead of travelingabout a periphery of the bottom of the emitter body 20, or may bedesigned with a zigzag pattern to form a tortuous path to further assistin reducing pressure of the fluid passing through the emitter body 20(similar to that of the flow path 50, which will now be discussed infurther detail).

With respect to the fluid that makes it through the passageways definedby ribs 25-29 and into the inlet channel 31, this fluid passes throughthe inlet opening 30 and enters a pressure-reducing flow channel 50 thatproduces a significant reduction in pressure between the fluid flowingin the primary lumen of the supply conduit or drip line 70 and the fluidultimately emptying into and present in the emitter outlet area 40. Inthe form illustrated, the emitter body 20 defines opposed baffle wallsto create the pressure-reducing flow channel and, in a preferred form,has an inner baffle wall 51 that is surrounded by an outer baffle wall52 which extends about the inner baffle wall 51 in a generally U-shapedmanner to form a flow passageway that generally directs the water in aU-shaped direction of travel. More particularly, the inner and outerbaffle walls 51, 52 have alternating projections and recesses that forma tortuous passage and cause the fluid flowing therethrough to zigzagback and forth, reducing pressure with each turn the fluid makes. Theouter baffle wall 52 is defined by an outer rim or peripheral wall ofthe emitter body 20 and the inner baffle wall 51 extends from a portionof the outer rim or peripheral wall and into to the middle of theemitter body 20 to form a peninsula about which the fluid flows frominlet 30 to outlet 40. The upper surfaces of the emitter body preferablyhave a radius of curvature that tracks the radius of curvature of thetube 70 so that the emitter body 20 can be bonded securely to the innerwall of the tube 70 and create an enclosed pressure reduction passagefrom inlet 30 to outlet 40. In the form illustrated, the tortuouspassage is formed via alternating teeth extending from opposing surfacesof the inner and outer baffle walls 51, 52 and has a cross-section thatis generally rectangular in shape when the emitter body 20 is bonded tothe inner surface of the extruded drip line 70 (keeping in mind that theradius of curvature of the tube 70 will likely make the upper portion ofthe cross-section slightly curved and the side walls to be slightlywider at their top than at their bottom).

It should be understood, however, that in alternate embodiments thepressure-reducing flow channel 50 may be made in a variety of differentshapes and sizes. For example instead of having projections with pointedteeth, the baffles could be made with blunt or truncated teeth, withteeth that are angled or tapered, with curved or squared projectionsinstead of triangular shaped teeth, with projections of othergeometrical shapes or geometries, symmetric or asymmetric, etc.

In the form illustrated, the pressure-reducing flow channel 50 alsoincludes an intermediate bath 53 that the fluid pours into as it makesthe turn in the generally U-shaped direction of travel which furthercauses pressure reduction as the water is flowing from a smaller passageto a larger passage in the bath 53. After making the turn, the fluidpasses or zigzags through another section of the pressure-reducing flowchannel 50 and empties into outlet pool 40.

In addition to the pressure-reducing flow path 50, the emitter 10further includes a pressure compensating feature 60 which further allowsthe emitter 10 to compensate for increases in fluid pressure in theprimary lumen of the tube 70. More particularly, pressure compensatingfeature 60 allows the emitter 10 to maintain relatively constant outletfluid flow and pressure even though the inlet fluid pressure mayfluctuate from time-to-time. In the form illustrated, the pressurecompensating feature 60 is a two part pressure compensation mechanismthat comprises an elastomeric portion 61 capable of deflecting underpressure to reduce the cross-section of the pressure-reducing flowchannel 50 and regulate fluid flow through the emitter, and a movablebaffle portion 62 capable of changing the length of the flow channel tocompensate for changes in supply line 70 fluid pressure.

The elastomeric portion 61 being a deflectable portion of the emitterbody 20 that is moveable between a first position wherein at least aportion of the pressure-reducing flow channel 50 is of a firstcross-section and a second position wherein the at least a portion ofthe pressure-reducing flow channel 50 is of a second cross-section,smaller than the first cross-section to regulate fluid flow through theemitter. In the form illustrated, the floor 61 of the flow channel 50forms an elastomeric portion and raises and lowers in response toincreases and decreases in supply line 70 fluid pressure, respectively.Thus, when fluid pressure increases in the supply line 70, the floor 61of the flow channel 50 is pressed-up or deflected up into the flowchannel 50 thereby reducing the cross-section of the flow channel toregulate the flow of fluid through the emitter 10. Conversely, whenfluid pressure in the supply line 70 reduces, the floor of the flowchannel 50 retreats from the flow channel back to a normal positionwherein the floor is not deflected up into the flow channel therebyincreasing the cross-section of the flow channel to allow fluid to flowmore freely through the flow channel 50.

Although the above embodiment has been described with the floor of theflow path 50 deflecting up into the emitter flow path to reducecross-section size of the flow path to compensate for increases in fluidpressure, it should be understood that in alternate embodiments otheremitter surfaces could be designed to either create this deflection ontheir own or to cooperate with the floor or other surface so that bothdeflect in order to compensate for fluid pressure increases. Forexample, rather than having the floor deflect, the side walls and/orceiling of the flow channel 50 could be designed to deflect either incombination with any one of these items or on their own as the soledeflecting portion.

The second part of the pressure compensation mechanism 60 comprises amovable structure, such as movable baffle portion 62, which is capableof moving between a first low pressure position wherein the length ofthe flow channel 50 is of a first distance and a second high pressureposition wherein the length of the flow channel 50 is of a seconddistance wherein the length of the flow channel is longer than the firstdistance to compensate for increase pressure in the supply line 70. Moreparticularly, in the form illustrated, the movable baffle portion 62deflects up and down with the floor of the flow channel 50 to sealinglyengage and disengage the movable baffle portion 62 with the inner wallof the supply line 70, respectively, and thereby lengthen or shorten theextent of the flow channel for at least some fluid flowing therethroughto compensate for changes in supply line fluid pressure.

As best illustrated in FIGS. 1C, D and G, the movable baffle portion 62comprises a tapered portion of the central or inner baffle wall 51 thattapers down away from the inner surface of supply line 70 so that atlower fluid pressures in supply line 70, fluid flows through the inlet30 and first section (or upstream section) of flow channel 50 and thenover the top of the tapered baffle section 62, through the secondsection (or downstream section) of the flow channel 50 and then intooutlet pool 40. Fluid may flow through the remaining portion of the flowchannel 50 including intermediate bath 53 (located between the upstreamand downstream sections of the flow channel 50), but it does not have tonor does all of the fluid flow through these portions of the flowchannel 50 due to the gap between the upper surface of the tapered innerbaffle wall section 52 and the inner surface of tube 70. As fluidpressure increases in the fluid supply line 70 and as best illustratedin FIG. 1H, the floor of the flow channel 50 starts to deflect upwardsand into the flow channel 50 moving the tapered baffle section 62 towardthe inner surface of tube 70 thereby reducing the gap between these twountil the upper surface of the tapered baffle section 62 sealinglyengages the inner wall of the tube 70 thereby preventing fluid fromflowing over the top of the tapered baffle section 62 and lengtheningthe amount of the flow channel 50 through which all of the fluid mustflow and reducing fluid pressure and flow due to same.

The emitter body 20 further defines an outlet area 40 which forms a poolinto which the fluid that passes through inlet 30 and tortuous passage50 and pressure compensation mechanism 60 collects or gathers. An outletin outer supply line 70, such as opening 71, provides access to thefluid collected in the outlet pool 40 and, more particularly, providesan egress for the fluid to trickle or drip out of emitter 10.

Since the emitter 10 is made of an integral body 20, the outlet area 40is provided with obstructions or stops, such as posts or nubs 41, thatprevent the outlet area 40 from collapsing when the fluid pressure ofsupply line 70 raises to a level sufficient for deflecting the floor ofthe flow channel 50 into the flow channel 50 to reduce the cross-sectionof same and regulate fluid flow through the flow channel (or as themovable structure 62 moves from the first or low pressure position tothe second or high pressure position). In the form illustrated, theposts 41 extend away from the body 20 and are generally frustoconical inshape to make the posts easier to mold when the body 20 is molded. Inaddition, in a preferred form, the upper surfaces of the posts 41 have aradius of curvature common to the radius of curvature of the uppersurfaces of baffles 51, 52 and that corresponds with a second radius ofcurvature of the inner wall of tube 70. The solid nature of the bafflewalls 51, 52 and outer rim or peripheral wall of emitter body 20likewise prevent these portions of the emitter body 20 from collapsingwhen the fluid pressure of supply line 70 pushes the floor of the flowchannel 50 into the flow channel.

Although the form illustrated in FIGS. 1A-D shows the outlet 71 of outertube 70 as a round opening, it should be understood that in alternateembodiments this may be provided in a variety of different shapes andsizes. For example, in one form the outer tube outlet 71 may be providedin the form of a slit, such as an elongated narrow oval shape, insteadof a round hole. In other forms, the outer tube outlet 71 may furtherdefine a pressure reducing passageway such as a tortuous or zigzagpassage.

By using a unitary emitter body 20 to form the inlet 30, flow channel50, outlet 40 and pressure compensating mechanism 60 rather thanrequiring multiple parts to be constructed and assembled to form suchfeatures, the emitter 10 is much easier to manufacture and providessignificant cost savings due to the reduction in parts and materials,and assembly time. The body 20 may be made of any type of materialcapable of allowing for this type of movement for pressure compensation.In a preferred form, however, the body 20 is made of TPO having aDurometer reading ranging between 25 and 100, with the Durometer readingpreferably being between 50 and 75. In FIGS. 1I-J, data is provided forthe amount of deflection per increase in pressure for materials havingDurometer readings of 50 and 75, respectively. In these examples, datawas collected at location points 1 and 2, as indicated in FIG. 1B, withthe distance (or gap) between the inner surface of tube 70 and the uppersurface of the tapered inner baffle wall portion 62 being thirtythousandths of an inch (0.030″) at location point 1 and thirteenthousandths of an inch (0.013″) at location point 2, and the floorthickness of flow channel 50 being eight thousandths of an inch(0.008″). These distances being calculated when the tapered baffle wallportion 62 is at its normal position (or low pressure/non-deflectedposition) as illustrated in FIG. 1G.

As can be seen in comparing FIGS. 1I-J, a quicker movement of thetapered baffle wall portion 62 and corresponding lengthening of the flowchannel 50 can be achieved using a material with a lower Durometerreading (e.g., a softer material), whereas a more constant movement(almost linear at times) of the tapered baffle wall portion 62 may beachieved by using a material with a higher Durometer reading (e.g., aharder material). Thus, the specific application the emitter 10 isintended for may play a role in the material selected for emitter body20 (e.g., if a quicker lengthening of the flow channel 50 is desired amaterial with a lower Durometer reading will be used, whereas if a moregradual closing of the tapered baffle wall portion 62 and more graduallengthening of the flow channel 50 is desired a material with a higherDurometer reading will be used, etc.).

In order to ensure the consistency of operation for each emitter 10mounted to the extruded supply line 70, care is taken to make sure thatthe various portions of body 20 are constructed with consistentthickness and density from one emitter to the next and that thedistances between location points 1 and 2 and the inner surface ofsupply line 70 are maintained consistently from one emitter to the next.In doing so, the emitters 10 mounted to the supply line 70 shouldoperate in a uniform manner and produce common low pressure fluid flowand flow rates at their respective outputs 40 (e.g., the flow rate ofthe first emitter mounted in the supply line should operate the same asthe last emitter mounted in the supply line).

In an alternate form, the emitter and drip line may be made-up of amulti-part construction and/or use a multi-step manufacturing orassembly process. For example an emitter body of a first type ofmaterial may be combined with another type of material (e.g., astructure, a layer, a coating, etc.) that is more easily bonded toconventional drip tubing so that emitter can be bonded to the tubing ina more consistent manner and each emitter is ensured to work similar toone another. More particularly, since soft materials, such as silicon,do not always bond easily to the various types of conventional drip linetubing used in the industry, which is typically polyethylene tubing, theemitter body may be made-up of a combination of soft and hard materialsto assist in the bonding of the emitter to the extruded tubing and toprovide a process that can repeatedly bond such emitters to extrudedtubing so that there is no significant (if any) variance in bondingbetween the emitters bonded to the tubing.

For example, by combining a soft material like silicon with a hardmaterial like a polyethylene, the hard portion of the emitter may moreeasily be bonded to the extruded tubing in a uniform and repeatablefashion. Although this form of emitter and tubing may be considered bysome to be a two-part construction, it would preferably remainhousingless and the soft portion of the emitter would make up themajority of the component. For example, in one form the hard portion ofthe emitter would simply comprise a polyethylene coating applied to anupper surface of the emitter to assist in consistently bonding theemitter to the inner surface of the drip line tubing in a manner thatcan be repeated easily from emitter to emitter. Not all of the uppersurfaces of the emitter body need to be coated with the polyethylenecoating and/or connected to the inner surface of the drip line tubing.Thus, in this example, the emitter continues to comprise a singular oruniform structure through which fluid flows that simply has a bondinglayer or agent of polyethylene which assists in connecting the emitterto the inner surface of the drip line tubing. In addition, thisconfiguration would still produce an emitter that can process gritbetter than conventional emitters, including those with multi-parthousings, diaphragms and metering grooves. In alternate forms, truetwo-piece constructions may be used to form the emitter body if desiredwith either piece making up a majority of the structure or bothmaking-up equal portions of the structure and/or either piece or bothmaking up portions of the inlet, flow channel or outlet as desired.

Turning now back to FIGS. 1A-F, a housingless irrigation drip emitter 10is provided for attachment to only a portion of an inner circumferenceof an inner surface of an irrigation drip line tube 70 having anelastomeric emitter body 20 integrally defining an inlet 30 forreceiving pressurized fluid from a fluid supply source, an outlet area40 for discharging the fluid from the body 20, a pressure reducing flowpath 50 extending between the inlet 30 and the outlet area 40 forreducing the pressure and flow of fluid received at the inlet 30 anddischarged through the outlet area 40, and a pressure compensatingportion 60 for automatically adjusting the pressure and fluid flowreducing effect of the flow channel 50 in response to a change inpressure of the fluid supply source 70, wherein the pressure reducingflow channel 50 includes an inner baffle wall 51 and an outer bafflewall 52 that extends about the inner baffle wall 51 in a generallyU-shaped manner. The baffle walls 51, 52 having upper surfaces that havea first radius of curvature that corresponds with a second radius ofcurvature of an inner wall of the irrigation drip line tube 70, and theinner baffle wall 51 having a first portion of constant height and asecond portion 62 of tapering height, the second portion 62 beingmovable between a first position wherein the upper surface of the secondportion 62 is not level with the upper surface of the first portion suchthat fluid can flow over the upper surface of the second portion atpredetermined low fluid pressures and a second position wherein theupper surface of at least a portion of the second portion 62 is levelwith the upper surface of the first portion and fluid cannot flow overthe level upper surfaces of the second portion 62 such that thecross-section of the flow channel is reduced and the length of the flowchannel is effectively lengthened.

In the form illustrated, the baffles of the inner and outer baffle walls51, 52 do not close sequentially when the second portion 62 of innerbaffle 51 moves from the first position to the second position, butrather, the teeth of the baffle walls 51, 52 on opposite ends of theflow passage 50 (i.e., some on the inlet end and some on the outlet end)close at the same time. This allows the moving portion 62 of innerbaffle 51 to gradually lengthen the extent of the flow passage 50 assupply line fluid pressure increases and to gradually shorten the extentof the flow passage 50 as supply line fluid pressure decreases withouthaving to worry about trying to sequentially close the baffles of thepressure-reducing passage 50.

In alternate embodiments, it should be understood that alternateportions of the emitter body 20 may be moved to compensate for increasesin fluid line pressure, either in conjunction with or in lieu of thosediscussed above. For example, in one alternate form, the emitter body 20may be designed so that additional sections of the baffle walls 51, 52may be moved to compensate for pressure increases in the supply line 70.More particularly and as illustrated in FIGS. 2A-D, both the innerbaffle wall and outer baffle wall may be designed to move and lengthenthe flow path to compensate for increases in supply line fluid pressure.For convenience, items which are similar to those discussed above withrespect to emitter 10 in FIGS. 1A-F will be identified using the sametwo digit reference numeral in combination with the prefix “1” merely todistinguish one embodiment from the other. Thus, the emitter bodyidentified in FIGS. 2A-D is identified using the reference numeral 120since it is similar to emitter body 20 discussed above. Similarly, theinlet, outlet and pressure-reducing flow channel are identified usingreference numerals 130, 140 and 150 since they are similar to theabove-mentioned inlet, outlet and flow channel 30, 40 and 50.

While the emitter body 120 of FIGS. 2A-F defines both apressure-reducing flow channel 150 and a two part pressure compensatingmechanism 160 having an elastomeric portion 161 and movable baffleportion 162 like the embodiment of FIGS. 1A-H, the movable baffleportion 163 in FIGS. 2A-F is made up of portions of the inner and outerbaffle walls 151, 152 rather than just the inner baffle wall 151. Moreparticularly, the inner and outer baffle walls 151, 152 move tocompensate for fluid pressure increases and decreases in the supply linefluid. In the form illustrated, the central or inner baffle wall 151tapers at its distal end into a tapered tongue-type structure orprojection 163 to form a first movable structure and the outer bafflewall 152 defines a mating fork or groove-type structure 164 thatcorresponds in shape to the tongue-type structure 163 to form a secondmovable structure.

As best illustrated in FIG. 2F, the tongue and fork or groove structures163, 164 cooperate with one another so that when the floor 161 of theflow channel 150 rises in response to increases in supply line pressure,the tapered structures 163, 164 both rise toward the inner surface ofthe tube 170 thereby reducing the amount of fluid that can flow over theupper surfaces of the tapered structures 163, 164 and effectivelylengthening the flow channel 150 and reducing the cross-section of theflow channel 150 to compensate for the increase in supply line fluidpressure. Similarly, when the floor 161 of flow channel 150 falls inresponse to a decrease in supply line pressure, the tapered structures163, 164 both move away from the inner surface of the tube 170 therebyincreasing the amount of fluid that can flow over the top of the uppersurfaces of the tapered structures 163, 164 and effectively shorteningthe length of the flow channel 150 and increasing the cross-section ofthe flow channel 150 to compensate for the decrease in supply line fluidpressure as illustrated in FIG. 2E.

In the form illustrated, the upper surfaces of the tapered structures163, 164 never fully seal against the inner wall of the tube 170 whenmoved to their high pressure position, however, in alternate forms, thetapered structures 163, 164 could be designed such that this occurs ifdesired. Similarly, the embodiment of FIGS. 1A-H could be designed sothat the upper surface of the tapered baffle section 62 does not sealcompletely against the inner surface of the tube 70, if desired.

It should be understood that in alternate embodiments the first andsecond movable structures 163, 164 of the inner and outer baffle walls51, 52 could be swapped so that the inner baffle wall 51 terminated in agroove-type structure and the outer baffle wall 52 defined a tongue-typestructure, or in yet other forms both could define other structuresmeant to correspond with one another or mesh with one another to achievethe same effect of lengthening and shortening the flow channel 50 inresponse to increases and decreases in supply line fluid pressure,respectively, and if desired, reducing and increasing the cross-sectionof the flow channel 150 in response to increases and decreases in supplyline fluid pressure, respectively. For example, in alternate forms, boththe inner and outer baffle walls 51, 52 could define structures thatcorrespond in shape with one another including but not limited tointermeshing U- or V-shaped structures that lengthen the flow channel150 and reduce the cross-section of the flow channel 150 in response toincreases in fluid pressure and that shorten the flow channel 150 andincrease the cross-section of the flow channel 150 in response todecreases in fluid pressure.

Thus, with this configuration an irrigation drip emitter 110 is providedfor attachment to only a portion of an inner circumference of an innersurface of an irrigation drip line tube 170 having an elastomericemitter body 120 integrally defining an inlet 130 for receivingpressurized fluid from a fluid supply source, an outlet area 140 fordischarging the fluid from the body 120, a pressure reducing flow path150 extending between the inlet 130 and the outlet area 140 for reducingthe pressure and flow of fluid received at the inlet 130 and dischargedthrough the outlet area 140, and a pressure compensating portion 160 forautomatically adjusting the pressure and fluid flow reducing effect ofthe flow channel 150 in response to a change in pressure of the fluidsupply source 170, wherein the pressure reducing flow channel 150includes an inner baffle wall 151 and an outer baffle wall 152 thatextends about the inner baffle wall 151 in a generally U-shaped manner.At least some of the upper surfaces of the baffle walls 151, 152 havinga first radius of curvature that corresponds with a second radius ofcurvature of an inner wall of the irrigation drip line tube 170 and theinner baffle wall 151 defines a first tapered baffle structure 163 andthe outer baffle wall 152 defines a second tapered baffle structure 164positioned proximate the first baffle structure 163, with the first andsecond tapered baffle structures 163, 164 cooperating to form part ofthe pressure reducing flow channel 150 and the first and second taperedbaffle structures 163, 164 tapering in height toward one another andbeing variably movable between a first position wherein the uppersurfaces of the first and second tapered baffle structures 163, 164 arenot level with the upper surfaces of the baffle walls with the firstradius of curvature so that fluid can flow over the first and secondtapered baffle structures 163, 164 and a second position wherein theupper surfaces of the tapered baffle structures 163, 164 move towardand/or are at the same level as the other upper surfaces of the bafflewalls with the first radius of curvature and fluid is restricted fromflowing over at least a portion of the first and second tapered bafflestructures 163, 164 and the cross-section of the flow channel 150proximate the first and second baffle structures 163, 164 is reduced andthe length or extent of the flow channel 150 is lengthened.

In yet other embodiments, the two part pressure compensating mechanismmay use other types of movable walls in combination with a deflectingmember to compensate for changes in fluid pressure. For example, in thealternate embodiment illustrated in FIGS. 3A-G, the emitter body isdesigned with a plurality of fluid inlet openings with sleeves orannular walls extending therefrom, which can move in response toincreases and decreases in supply line fluid pressure. For convenience,items which are similar to those discussed above with respect to emitter10 in FIGS. 1A-F and emitter 110 in FIGS. 2A-F will be identified usingthe same two digit reference numeral in combination with the prefix “2”merely to distinguish this embodiment from the others. Thus, the emitterbody identified in FIGS. 3A-F is identified using the reference numeral220 since it is similar to emitter bodies 20 and 120, and defines aninlet 230, outlet 240 and pressure-reducing flow channel 250, which aresimilar to those discussed above (i.e., inlet 30, 130, outlet 40, 140,and pressure-reducing flow channel 50, 150). In addition, the uppersurfaces of the peripheral wall of emitter body 220, inner and outerbaffle walls 251, 252, and nubs 241 all have a first common radius ofcurvature that corresponds with a second radius of curvature of an innerwall of the irrigation drip line tube 270.

Unlike the embodiments discussed above, however, the inlet 230 ofemitter body 220 comprises a plurality of inlet openings 232, 233, 234,235, 236 and 237. In the form illustrated, the inlet openings 232-237vary in height, with the initial inlet opening 232 being flush to thefloor 261 of the pressure-reducing flow channel 250 and the remaininginlet openings 233-237 having annular walls, such as sleeves or bosses233 a, 234 a, 235 a, 236 a and 237 a, respectively, that have terminalends that progressively extend further into the pressure reducing flowchannel 250 with the terminal end of each boss moving variably from anopen position wherein the terminal end of the boss is not generallylevel or flush with the first common radius of curvature of the uppersurfaces of the baffle walls 251, 252 so that fluid can flow through theboss and into the flow channel 250, and a closed position wherein theterminal end of the boss is generally level or flush with the firstcommon radius of curvature of the upper surfaces of the baffle walls251, 252 so that fluid is prevented from flowing through the boss andinto the flow channel 250.

In a preferred form, the upper surfaces of the terminal end of thebosses 233 a-237 a have a radius of curvature that is the same as thefirst common radius of curvature of the upper surfaces of baffle walls251, 252 which corresponds with the second radius of curvature of theinner wall of the irrigation drip line tube 270 so that the bosses 233a-237 a can close flush against the inner wall of tube 270 and preventfluid from flowing through the boss and into the flow channel 250 whenraised into engagement with the inner wall of tube 270. In addition, theheight of the bosses 233 a-237 a are varied so that the inlets 233-237close sequentially starting with the inlet furthest from the initialinlet opening 232 (i.e., which in the illustrated example is inlet 237)and then moving to the inlet that is the next furthest (i.e., 236), thenthe next furthest (i.e., 235) and so on. By closing the inlets 233-237in this order (i.e., starting with the inlet furthest downstream andmoving upstream), the emitter body 220 actually lengthens thepressure-reducing passage 250 with each sequential closing for all fluidflowing therethrough which allows the emitter to compensate forincreases in the supply line fluid pressure. Conversely, as supply linefluid pressure decreases, the emitter body opens the inlets 233-237beginning with the inlet furthest upstream and moving downstream, whichallows the emitter to shorten the pressure-reducing passage 250 for someof the fluid flowing through the emitter to compensate for the reductionin supply line fluid pressure.

In the form illustrated, it is contemplated that each of inlet openings233-237 will close during normal operation of the emitter 210 or thatthe emitter body 220 will be designed such that inlet openings 233-237will normally close at some point during the operation of the emitterdue to expected increases in supply line fluid pressure (i.e., thatenough pressure is expected to be reached that will cause inlets 233-237to close at some point or another). However, it should be understoodthat in alternate embodiments the emitter body 220 may be designed toonly shut one or more of the inlets 233-237 during normal or expectedsupply line fluid pressure conditions and only having the remaininginlets 233-237 close under extraordinary conditions (e.g., when supplyline fluid pressures are reached that are much greater than normal orexpected pressures). This can either be done by altering the size of theemitter body 220 or any of its features (e.g., inlet opening, floorthickness, baffle wall size, flow path cross-section, etc.) or by usingdifferent materials for body 220 (e.g., materials with differentDurometer values, different compositions that make the body 220 harderor less flexible, etc.). Conversely, the emitter body 220 may be made ofmaterials that allow for inlets 233-237 to close more rapidly if desired(e.g., by altering body features and/or selecting different materials asdiscussed above). In this way, the emitter 10 can be customized forspecific applications.

Thus, with this configuration an irrigation drip emitter 210 is providedfor attachment to only a portion of an inner circumference of an innersurface of an irrigation drip line tube 270 having an elastomericemitter body 220 integrally defining an inlet 230 for receivingpressurized fluid from a fluid supply source, an outlet area 240 fordischarging the fluid from the body 220, a pressure reducing flow path250 extending between the inlet 230 and the outlet area 240 for reducingthe pressure and flow of fluid received at the inlet 230 and dischargedthrough the outlet area 240, and a pressure compensating portion 260 forautomatically adjusting the pressure and fluid flow reducing effect ofthe flow channel 250 in response to a change in pressure of the fluidsupply source 270, wherein the pressure reducing flow channel 250includes an inner baffle wall 251 and an outer baffle wall 252 thatextends about the inner baffle wall 251 in a generally U-shaped manner.With at least some upper surfaces of the baffle walls 251, 252 having afirst common radius of curvature that corresponds with a second radiusof curvature of an inner wall of the irrigation drip line tube 270, andthe inlet 230 includes a plurality of inlet passages 232-237 with eachpassage 232-237 extending from a surface of the body exposed to thepressurized fluid to the pressure reducing flow channel 250, with atleast some of the inlet passages 233-237 extending through bosses eachhaving a terminal end progressively extending further into the pressurereducing flow channel 250, the terminal end of each boss being movablevariably from an open position wherein the terminal end of the boss isnot level with the upper surfaces of the baffle walls having the firstradius of curvature so that fluid can flow through the boss and into theflow channel 250 and a closed position wherein the terminal end of theboss is generally level with the upper surfaces of the baffle wallshaving the first radius of curvature so that fluid is prevented fromflowing through the boss and into the flow channel 250.

It should be understood that in alternate embodiments the sleeves orbosses 233 a-237 a may take on other shapes and sizes as may be desiredfor specific applications. For example, in some applications inlets withrectangular cross sections may be desired over the round inlets depictedin FIGS. 3A-G. In yet other forms, inlet passages that serve some formof pressure reduction, such as passages that define tortuous paths, maybe desired. In still other embodiments, fewer or more inlet openings orbosses may be provided than those shown in FIGS. 3A-G if desired. Forexample, in FIG. 4, an alternate drip emitter and drip line isillustrated having an inlet made-up of a plurality of inlet openings. Inkeeping with the above practice, features that are common to thosediscussed above will use the same two-digit reference numeral, buthaving the prefix “3” merely to distinguish one embodiment from another.

In the form illustrated in FIG. 4, the plurality of inlets are shapedlike elongated openings, such as slits or slots 330, which not onlyallow fluid to flow through the inlet of the emitter 310, but also helpfilter or deflect particulates such as grit away from the emitter 310 tohelp ensure the fluid flowing through the emitter 310 is free of suchparticulates so that the particulates do not interfere with theoperation of the emitter 310. The plurality of openings 330 havelongitudinal axes that parallel the longitudinal axis of the emitter310, however, in alternate forms it should be understood that theplurality of openings may take on a variety of different shapes andsizes and may be oriented in different ways so as not to havelongitudinal axes parallel to the longitudinal axis of the emitter 310(if even having longitudinal axes).

In alternate forms, it should be understood that the inlet or inlets ofthe emitter may be placed in certain positions to help determine how theemitter will operate. For example, in some forms, an inlet opening maybe positioned further upstream to effectively shorten the length of thepressure-reducing flow channel and create an emitter that has a higherfluid flow rate (e.g., four gallons per hour or 4 GPH). In another formthe inlet opening may be positioned further downstream to effectivelylengthen the pressure-reducing flow channel and create an emitter thathas a lower flow rate (e.g., 1 GPH). In still another form, the inletopening may be positioned somewhere in-between the above mentionedlocations to create an emitter with an intermediate pressure-reducingflow channel length that has a flow rate somewhere in-between the otherflow rates (e.g., 2 GPH). The changing of this inlet location could beaccomplished by having a readily adjustable mold (e.g., one where thelocation of the inlet opening can be slid or moved between the desiredlocations) or, alternatively, separate molds could be made for eachembodiment (i.e., one for the low flow rate emitter, another for theintermediate flow rate emitter, and another for the high flow rateemitter).

The same may be true for outlet openings. For example, whenmanufacturing the drip line, the location of the outlet opening may bealtered to affect how the emitter will operate. The outlet opening couldbe located further upstream to effectively shorten the pressure-reducingflow channel and create an emitter with a higher flow rate (e.g., 4GPH). In another form the outlet opening may be located furtherdownstream to effectively lengthen the pressure-reducing flow channeland create an emitter with a lower flow rate (e.g., 1 GPH). In anotherform, the outlet opening may be positioned somewhere between the abovementioned locations to effectively create an emitter with anintermediate pressure-reducing flow channel length that operates with afluid flow rate somewhere between the above-mentioned flow rates (e.g.,2 GPH). The outlet opening may be formed in the drip line tubing beforeor after the emitter is bonded to the inner surface of the tubing,however, in a preferred form the opening will be formed after theemitter is bonded to the inner surface of the tubing. The opening istypically formed via a die, press, awl or the like. Thus, adjustments tothe location of where the outlet opening can be made by adjusting wherethis puncture occurs in the tubing.

In addition, in some forms color may be added to the individual emittersand/or the drip line and methods of manufacturing same to distinguishthese products or product lines from one another or to signify somethingrelating to the items intended use or application. For example, onecolor may be used to identify an emitter or dip line that drips at arate of one gallon per hour (1 GPH), another color may be used toidentify an emitter or drip line that drips at a rate of two gallons perhour (2 GPH), another color may be used to identify an emitter or dripline that drips at four gallons per hour (4 GPH). In one form, emittersof different flow rates are distinguished by color so that workers canmore easily determine which emitters are to be inserted into extrudedtubing during assembly in order to obtain a drip line with commonemitter drip rates. In another form, the extruded tubing may be made ina specific color or have a marking of a specific color to designate theflow rate of the drip emitters located therein in order to help workersand/or end users distinguish drip lines of different drip rates. Instill other forms, both the emitters and the tubing may include color tospecify the drip rate or intended application. In other forms, colorsmay be used to signify the source of fluid to be used with the emitteror drip line or the particular application for which the emitter or dripline is to be used. For example, the color purple is often used toindicate that reclaimed or recycled water is being used. Thus, theemitter or drip line could be marked with this color to indicate thatthe emitter or drip line is intended for these types of applications orto indicate the type of fluid that is suppose to travel through thesetypes of emitters/drip lines. If desired, any of the embodiments andmethods disclosed herein could include the addition of color for suchpurposes.

Turning back to the embodiment of FIG. 4, it should be appreciated thatin this form, the emitter 310 includes a baffle design having teethextending from the sides of the emitter body 320 toward one another toform the tortuous flow passage 350 without a central baffle portion. Theheight of each tooth is higher at the sides of the emitter body 320 thanat the distal end of each tooth and, as fluid pressure increases, thefloor 361 of flow channel 350 moves up toward the inner surface of thetube 370 causing the portions of the teeth closest to the sides of theemitter body 320 to close against (e.g., touch, engage, etc.) the innersurface of the tube 370 first, before gradually closing more and more ofeach tooth against the inner surface of tube 370 simultaneously untilthe floor 361 cannot move any further. Thus, rather than closing thebaffle teeth consecutively or sequentially against the inner surface oftube 370 to lengthen the pressure-reducing flow passage 350 andcompensate for the increase in pressure, this configuration allows eachtooth to gradually close against the inner surface of tube 370simultaneously in response to increases in line pressure therebylengthening the pressure-reducing flow passage 350 and reducing thecross-section of the pressure-reducing flow channel 350 to form apressure compensating mechanism 360 that compensates for increases anddecreases in line pressure. For convenience, only a portion of tube 370is illustrated in FIG. 4 so that a portion of the emitter body 320remains visible, however, it should be understood that the tube 370would extend over the entire emitter body 320 and that the emitter body320 would be bonded to the inner surface of the tube in a manner similarto that discussed above.

In the form illustrated, fluid flowing through the drip line 370 entersthe emitter 310 via inlet openings 330, travels through the tortuouspassage 350 and then exits the emitter 310 via outlet opening 371. Thepressure compensating mechanism 360 reduces the cross-section of theflow channel 350 by raising the floor 361 of flow channel 350 andpressing more of the upper surfaces of the baffle teeth into engagementwith the inside surface of the tubing 370 as fluid pressure increases,and increases the cross-section of the flow channel 350 by allowing thefloor 361 of flow channel 350 to move away from the inner surface oftubing 370 as fluid pressure decreases. This configuration also providesa large central flow path down the middle of the pressure-reducing flowchannel 350 which allows for easier processing of grit or otherparticulates, particularly at start-up and shutdown of fluid flow due tothe low pressures associated with same and due to the fact the portionof the flow channel 350 with the largest cross-sectional area willalways remain in the middle of the emitter 310 and, specifically, at thelongitudinal axis of the flow channel 350.

FIGS. 5A-B are perspective views of an alternate drip emitter and dripline embodying features of the present invention wherein thepressure-reducing flow channel is made-up of baffles with flexible teeththat move in response to fluid flow through the emitter body. In keepingwith above practices, items that are common to those discussed abovewill use the same two digit reference numeral but with the addition ofthe prefix “4” to distinguish one embodiment from another. In the formillustrated, only a portion of the tube 470 is illustrated in FIG. 5A sothat the details of emitter body 420 may be seen, however, it should beunderstood that the entire emitter body 420 would be inserted within thetube 470 and connected to an inner surface of tube 470.

The emitter 410 includes a plurality of flexible baffle walls extendingfrom opposite sides of the emitter body 420 toward one another and in astaggered arrangement so one wall is not directly opposite a wall on theother side of the emitter body 420. In the form illustrated, the bafflewalls form flexible teeth that are much narrower than those discussedabove and form generally rectangular walls connected at their base tothe floor 461 of the pressure-reducing flow channel 450 and on one sideto the side of the emitter body 420. Thus, when fluid flows through thesupply line 470, at least a portion of the fluid flows through the inletopening 430, through the tortuous passage 450 defined by the bafflewalls 452, to the outlet 440 and through outlet opening 471. As thesupply line fluid pressure increases, the floor of the flow channel 461moves toward the inner surface of tube 470 driving the tops of thebaffle walls into engagement with the inner surface of the supply linetubing 470 and, thereby, restricting or reducing the cross-sectionalarea of the flow channel 450 and/or increasing the length of the flowchannel 450 in response to the increase in pressure in order tocompensate for the supply line fluid pressure increase. As the fluidpressure in the supply line continues to increase, the baffle walls 452closest to inlet 430 flex or bend over in the direction of the fluidflow. This occurs because the pressure of the fluid is always greaterthan the pressure of the floor 461 raising the baffle walls 452 intoengagement with the inner surface of the tube 470. As fluid pressureincreases further within tube 470, more and more of the flexible bafflewalls 452 will flex or bend in the direction of the fluid flow which canalso help the emitter process obstructions such as grit or otherparticulates by allowing the baffle walls to bend so that theobstructions can be carried through the flow channel and out of theemitter 410. Conversely, when fluid pressure decreases in the supplyline 470, the baffle walls cease bending and return to their normalpositions (e.g., as illustrated in FIG. 5A) and the floor 461 lowers,allowing the walls 452 to move away from the inner surface of tube 470and thereby increasing the cross-sectional area of the flow path 450and/or reducing the length of the flow channel 450 to account for thedecrease in fluid pressure. In this way, emitter 410 is equipped with apressure compensating mechanism 460 like some of the other embodimentsdiscussed herein.

Although the embodiment illustrated shows circular inlets and outletopenings 430 and 471, it should be understood that in alternateembodiments these inlet and outlet openings may take on a variety ofdifferent shapes and sizes. In addition, in alternate forms the emitterbody 420 may be designed with larger pools or baths located at the inlet430 and outlet 440 (like the embodiment of FIGS. 1A-H), instead ofdirectly transitioning to the tortuous flow passage 450 as illustratedin FIGS. 5A-B. Furthermore, the flexible baffle walls 452 disclosed inthis embodiment could easily be used in any of the other embodimentsdisclosed herein, just like any of the features of the variousembodiments discussed herein could be mixed and matched together to formanother embodiment regardless of which embodiment the specific featureis currently illustrated in. Thus, in one form, the flexible teeth 452may be used in an embodiment more like that shown in FIGS. 1A-H (e.g.,with a U-shaped tortuous passage). In still other forms, the flexibleteeth 452 may be attached to the emitter body 420 in such a way as to bepredisposed to flex or bend in a preferred direction. For example,rather than having the flexible teeth 452 bend in the same direction thefluid flows through the emitter 410, the teeth 452 could be predisposedwith an angle causing the teeth 452 to bend in a direction opposite thefluid flow in order to cause more turbulence and interference with thefluid flowing through the emitter 410. As mentioned above, however, in apreferred form of the embodiment of FIGS. 5A-B, the baffle walls 452will bend in the same direction as the fluid flow.

Yet another embodiment of an alternate drip emitter and drip line inaccordance with the invention is illustrated in FIGS. 6A-D. As with theother embodiments discussed herein, this embodiment will use the sametwo digit reference numeral to refer to items similar to those discussedabove, but will include the prefix “5” to distinguish one embodimentfrom the others. Thus, in the form illustrated in FIGS. 6A-D, theemitter 510 includes an emitter body 520 having an inlet 530, outlet 540and tortuous flow path 550 extending therebetween; however, unlike theprevious embodiments discussed herein, the baffle walls 552 include atleast one hollow portion which fills with fluid as the supply line fluidpressure increases in order to reduce the cross-sectional area and/orincrease the length of the flow channel 550 to compensate for anincrease in fluid pressure.

More particularly, in the form illustrated in FIGS. 6A-D, the teeth 552of the baffle walls are hollowed-out or define an opening or void 554 inorder to allow supply line fluid to fill the void 554 of the hollowteeth 552 (or the space 554 defined by each hollow tooth) and, as supplyline fluid pressure increases, to swell or enlarge the size of eachtooth 552 by filling this void with pressurized fluid and therebycausing the size of the teeth to grow/expand and reduce thecross-sectional area of the flow channel 550 to compensate for theincrease in the fluid pressure. A view of the bottom of emitter body 520(which is the side of the emitter facing the fluid flowing throughsupply line 570) is illustrated in FIG. 6D showing the void 554 andillustrating how some of the supply line fluid is able to flow along thebottom surface of the emitter body 520, fill the voids 554 of the hollowteeth, enter the inlet 530 of the emitter and/or continue flowing downthe supply line 570.

As fluid pressure increases, the floor of the emitter 561 will also moveupwards and, thus, the upper surfaces of the baffle walls 552 willgradually engage more and more of the inner surface of tube 570 therebyincreasing the length of the tortuous passage 550 that the fluid mustflow through in order to compensate for the increase in fluid pressure.Conversely, when fluid pressure decreases, the floor 561 will drop,gradually disengaging the baffle walls 552 from the inner surface of thetube 570 and the teeth 552 will shrink or reduce in size to effectivelyincrease the cross-sectional area of the flow path 550 and reduce thelength of the tortuous passage that the fluid must flow through tocompensate for the reduction in fluid pressure. Thus, like the previousembodiments discussed herein, the emitter 510 is equipped with both apressure-reducing flow path 550 and a pressure compensating mechanism560 for ensuring that each emitter operates uniformly and as desired.

In FIG. 6A, the supply line fluid pressure is low and, thus, the teethof baffle walls 552 are not enlarged and the upper surfaces of thebaffle walls are not fully engaged with the inner surface of the supplyline tube 570. This reduces the length of the flow channel 550 that thefluid must flow through and allows for the flow channel 550 to have amaximum cross-sectional area. In FIG. 6B, the supply line fluid pressurehas increased some to a generally intermediate level of pressure suchthat the teeth of baffle walls 552 have enlarged a bit and the uppersurfaces of the baffle walls nearest the side of emitter body 520 beginto engage the inner surface of supply line tube 570. This increases thelength of the flow channel 550 that the fluid must flow through andreduces the cross-sectional area of the flow channel 550 to account foror compensate for the increase in fluid pressure. In FIG. 6C, the supplyline fluid pressure has increased further to a high level of pressuresuch that the teeth of the baffle walls 552 have grown or enlarged totheir maximum size (or close to their maximum size) and the uppersurfaces of the baffles fully engage the inner surface of the supplyline tube 570. This further increases the length of the flow channel 550that the fluid must flow through (thereby maximizing the amount ofpressure-reduction taking place via flow channel 550) and reduces thecross-sectional area of the flow channel 550 to its smallestcross-sectional area to compensate for the increase in fluid pressure.In addition, the baffle teeth 552 in FIG. 6C are shown tipping orbending in the direction of the fluid flow (similar to that shown withrespect to the embodiment of FIGS. 5A-B). Thus, with this configuration,the pressure-reducing flow channel has a first cross-sectional area atlower fluid pressures, a second cross-sectional area, smaller than thefirst, at higher fluid pressures to compensate for the increase in fluidpressure so that the emitter and drip line trickle fluid at a generallyconstant or desired rate, and a plurality of gradually decreasingcross-sectional areas as the fluid pressure increases from the pressurethat exists at the first cross-sectional area to the pressure at thesecond cross-sectional area.

FIGS. 6B-C are perspective views of a portion of the flow channel ofFIG. 6A illustrating the hollow teeth of the baffle partially enlargedand fully enlarged, respectively, in response to increasing fluidpressure showing how the cross-sectional area of the pressure-reducingflow channel in FIG. 6B has a smaller cross-sectional area than thatillustrated in FIG. 6A due to an increase in fluid pressure and showinghow the cross-sectional area of the pressure-reducing flow channel ofFIG. 6C is even smaller than that illustrated in FIG. 6B due to afurther increase in fluid pressure.

In addition to the above embodiments, it should be understood thatvarious methods of manufacturing or assembling irrigation drip lines,methods of compensating for pressure in a supply line (e.g., increasesor decreases in supply line fluid pressure), methods of manufacturing anemitter and methods of reducing fluid flow pressure are also disclosedherein. For example, a method of assembling an irrigation drip line isdisclosed which comprises providing a drip emitter according to any ofthe above mentioned embodiments where at least one of the inner andouter baffle walls include a tapered baffle wall section, extruding adrip line tube and inserting the provided drip emitter into the dripline tube as it is extruded such that upper surfaces of the emitterother than the tapered baffle wall section are bonded with an innersurface of the extruded drip line tube to form a sealed engagement sothat a pressure reduction flow channel is formed between the inlet andoutlet area of the emitter. In a preferred form, the upper surfaces ofthe non-tapered baffle walls are bonded to the inner surface of theextruded drip line tube to form this sealed engagement so that anelongated tortuous passage is formed between the inlet and outlet of theemitter.

In addition to this method, there are disclosed several methods ofcompensating for pressure in irrigation drip emitters. For example, amethod of compensating for pressure in an irrigation drip emitter isdisclosed comprising providing a drip emitter according to any of theabove-mentioned embodiments wherein the baffle walls have upper surfaceswith a first radius of curvature and the inner baffle wall has a firstportion of constant height and a second portion of tapering height thatis variably movable between a first low pressure position wherein theupper surface of the second portion is not generally level with theupper surface of the first portion and fluid can flow over the uppersurface of the second portion at low fluid pressures and a second highpressure position wherein the upper surface of the second portion islevel with the upper surface of the first portion such that fluid isprevented from flowing over the upper surface of the second portion andthe cross-section of the flow channel is reduced and the extent of theflow channel is effectively lengthened, and moving the second portion ofthe inner baffle wall between the first low pressure position whereinthe upper surface of the second portion is not level with the uppersurface of the first portion and fluid can flow over the upper surfaceof the second portion at low fluid pressures and the second highpressure position wherein the upper surface of the second portion islevel with the upper surface of the first portion so that fluid isprevented from flowing over the upper surface of the second portion toreduce the cross-section of the flow channel and effectively lengthenthe extent of the flow channel the fluid has to pass through at highfluid pressure in order to compensate for an increase in fluid supplypressure, and moving variably the second portion of the inner bafflewall toward and/or to the second high pressure position to compensatefor an increase in fluid pressure and toward and/or to the first lowpressure position to compensate for a decrease in fluid supply pressure.

Alternatively, a method of compensating for pressure in an irrigationdrip emitter is disclosed which comprises providing a drip emitteraccording to any of the above-mentioned embodiments wherein the bafflewalls have upper surfaces with a first radius of curvature and the innerbaffle wall terminates in a first structure and the outer baffle wallincludes a second structure that generally corresponds in shape and/ormeshes with the first structure and is positioned proximate the firststructure, with the first and second structures tapering in heighttoward one another and being variably movable between a first lowpressure position wherein the upper surfaces of the tapered structuresare not level with the upper surfaces of the baffle walls and fluid canflow over the tapered structures at low fluid pressure and a second highpressure position wherein the upper surfaces of the tapered structuresare level with the upper surfaces of the baffle walls and fluid isprevented from flowing over the tapered structures to reduce thecross-section of the flow channel proximate the first and secondstructures and effectively lengthen the extent or amount of the flowchannel the fluid has to pass through at high fluid pressure, and movingvariably the first and second structures toward and/or to the secondhigh pressure position to compensate for an increase in fluid supplypressure and toward and/or to the first low pressure position tocompensate for a decrease in fluid supply pressure.

Alternatively, another method of compensating for pressure in anirrigation drip emitter is disclosed comprising providing an irrigationdrip emitter according to any of the embodiments disclosed herein,wherein the baffle walls have upper surfaces with a first radius ofcurvature and the inlet includes a plurality of inlet openings orpassages extending from a surface of the body exposed to the pressurizedsupply fluid to the pressure reducing flow channel, each inlet passageextending through a boss with a terminal end extending progressivelyfurther into the pressure reducing flow channel, each of the terminalends movable variably between an open position wherein the upper surfaceof the terminal end of the boss is not at the same general level as thebaffle walls (or with the upper surfaces of the terminal end and bafflewalls not being at a common radius of curvature) so that fluid cancontinue to flow through the boss and into the flow channel and a closedposition wherein the terminal end of the boss is generally level withthe upper surfaces of the baffle walls and has a generally common radiusof curvature as the first radius of curvature of the baffle walls sothat fluid is prevented from flowing through the boss or inlet sleeveand into the flow channel, and moving variably the inlet openings orterminal ends of the bosses toward and/or to the second high pressureclosed positions to compensate for a increase in fluid supply pressureand toward and/or to the first low pressure open positions to compensatefor a decrease in fluid supply pressure.

In the above examples, it should be clear that movement of the movablewalls or structures to compensate for fluid pressure increases anddecreases can either be complete movements from a first limit of travelto a second limit of travel (i.e., from a furthest most open position toa furthest most closed position and vice versa), or alternatively, maysimply be movements toward one or more of those limits of travel withoutthose limits actually having been reached (i.e., movement toward afurthest most open position to a furthest most closed position and viceversa). In addition, the material chosen for the emitter body (e.g., 20,120, 220 above), may be selected such that such movement happens at adesired pace. For example, if a quick opening and closing is desired, amaterial that is more flexible or has a lower Durometer value may beselected. Whereas, if a slower or more gradual opening and closing (ortransitioning from one or the other) is desired, a material that is lessflexible or that has a higher Durometer value may be selected.

There also are disclosed herein various methods for processing gritthrough an emitter or clearing emitters and/or drip lines ofobstructions. For example, one method for processing grit comprisesproviding an emitter of the type discussed above, adjusting the fluidpressure that the emitter is subjected to in a supply line to alter thesize or shape of the flow channel to expel any obstructions clogging theemitter (e.g., obstructions clogging an inlet, flow channel, outlet,etc.). In one form this is done by decreasing the fluid pressure tomaximize the cross-sectional area of the flow channel and/or create acentral flow channel through which any obstructions such as grit orother particulates may be flushed. In another form this is done byincreasing the fluid pressure to cause the baffle walls of the flowchannel to deflect, bend or tip so that obstructions can pass throughthe flow channel or be carried out of the emitter via the high pressurefluid passing therethrough.

Thus it is apparent that there has been provided, in accordance with theinvention, an elastomeric emitter and methods relating to same thatfully satisfies the objects, aims, and advantages set forth above. Whilethe invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives,modifications, and variations will be apparent to those skilled in theart in light of the foregoing description. Accordingly, it is intendedto embrace all such alternatives, modifications, and variations as fallwithin the spirit and broad scope of the appended claims.

1. A method of assembling an irrigation drip line comprising: providinga drip emitter comprising a discrete elastomeric emitter body integrallydefining: an inlet on a first side of the body for receiving pressurizedfluid from a fluid supply source; an outlet on a second side of the bodyfor discharging the fluid from the body; a flow channel extendingbetween the inlet and the outlet and having a pressure reduction portionhaving a plurality of non-tapered baffles and a pressure compensationportion having at least one tapered baffle; extruding a drip line tube;and inserting the drip emitter into the drip line tube as it is extrudedsuch that the non-tapered baffles bond with an inner surface of theextruded drip line tube to form a sealed engagement so that the pressurereduction portion is enclosed and the pressure compensation portionremains movable with respect to the drip line tube.
 2. The method ofclaim 1 wherein the emitter body defines a perimeter wall and insertingthe drip emitter comprises inserting the drip emitter into the drip linetube as it is extruded such that the perimeter wall and non-taperedbaffles bond with the inner surface of the extruded drip line tube toseal the emitter body to the drip line tube.
 3. The method of claim 2wherein the perimeter wall and the non-tapered baffles have uppersurfaces that track a radius of curvature of the inner surface of theextruded drip line tube and inserting the drip emitter comprises bondingthe upper surfaces of the perimeter wall and the non-tapered baffles tothe inner surface of the extruded drip line tube so that the emitterbody is bonded securely to the inner surface of the extruded drip lineand prevents fluid from flowing over the upper surfaces of the perimeterwall and the non-tapered baffles.
 4. The method of claim 2 wherein theemitter body has boundary walls that define at least a portion of theinlet, outlet and flow channel and each boundary wall has an uppersurface that tracks a radius of curvature of the inner surface of theextruded drip line tube and inserting the drip emitter comprises bondingthe upper surfaces of the boundary walls to the inner surface of theextruded drip line.
 5. The method of claim 2 wherein the at least onetapered baffle comprises two tapered baffles that extend in a V-shapedpattern and inserting the drip emitter comprises bonding the dripemitter to the inner surface of the extruded drip line tube such thatthe two tapered baffles remain movable between a first position whereinupper surfaces of the two tapered baffles are spaced from the innersurface of the extruded drip line tube and a second position wherein thetwo tapered baffles are moved toward the inner surface of the extrudeddrip line tube.
 6. A method of assembling an irrigation drip linecomprising: providing a drip emitter comprising a discrete elastomericemitter body having a perimeter wall having upper surfaces of a firstheight, the emitter body integrally defining: an inlet on a first sideof the body for receiving pressurized fluid from a fluid supply source;an outlet on a second side of the body for discharging the fluid fromthe body; a flow channel extending between the inlet and the outlet andhaving a pressure reducing portion and a pressure compensating portionhaving at least one baffle with an upper surface of a second heightdifferent from the first height of the perimeter wall in order to allowthe pressure compensating portion and the at least one baffle to movebetween a first, low fluid supply source pressure position and a second,high fluid supply source pressure position wherein the upper surface ofthe at least one baffle moves toward or to the first height when in thesecond, high fluid supply line pressure position; extruding a drip linetube; and inserting the drip emitter into the drip line tube as it isextruded such that the upper surfaces of the perimeter wall bond with aninner surface of the extruded drip line tube to form a sealed engagementso that the flow channel is enclosed between the inlet and outlet. 7.The method of claim 6, wherein the flow channel further includesnon-tapered baffles and the perimeter wall and the non-tapered baffleshave upper surfaces that track a radius of curvature of the innersurface of the extruded drip line tube and inserting the drip emittercomprises bonding the upper surfaces of the perimeter wall and thenon-tapered baffles to the inner surface of the extruded drip line tubeso that the emitter body is bonded securely to the inner surface of theextruded drip line and prevents fluid from flowing over the uppersurfaces of the perimeter wall and the non-tapered baffles.
 8. Themethod of claim 6 wherein the emitter body has boundary walls thatdefine at least a portion of the inlet, outlet and flow channel and eachboundary wall has an upper surface that tracks a radius of curvature ofthe inner surface of the extruded drip line tube and inserting the dripemitter comprises bonding the upper surfaces of the boundary walls tothe inner surface of the extruded drip line.
 9. The method of claim 6wherein the at least one tapered baffle comprises two tapered bafflesthat extend in a V-shaped pattern and inserting the drip emittercomprises bonding the drip emitter to the inner surface of the extrudeddrip line tube such that the two tapered baffles remain movable betweenthe first, low fluid supply source position and the second, high fluidsupply source position.